Azo dye and process of making same.



' Nrrno STATES Patented June 2, 1903.

PATENT QFFICE.

MYRTIL KAHN, OF ELBERFELD, GERMANY, ASSIGNORTO FARBENFA- BRIKEN OF ELBERFELD 00., on N W YORK, N. Y., A CORPORATION OF NEW YORK.

AZO DYE AND PROCESS oF MAKINGASAME.

SBECIFIGATION fOrIning part of Letters Patent No. 729, 601, dated June 2, 1903.

Application filed March 7,1903. $erial1lo. 146,741. (No specimens.)

To aZZ whom it may concern:

Be it known that I, MYRTIL KAHN, doctor of philosophy, chemist, residing at Elberfeld, Germany, (assignor to the FARBENFABRIKEN OF ELBERFELD (30., of New York,) have invented a new and useful Improvement in Monoazo Coloring-Matter; and I do hereby declare the following to be an exact and clear description of my invention.

My invention relates to the production of new and valuable azo dyestuffs by combining the diazo compounds of ortho-amidophenol sulfonic acids having the general formula:

soar X (X meaning a hydrogen atom which can be replaced by halogensNO SO l-l,0r OH such as ortho-a-midophenol sulfonic acids, ortho amidocresol sulfonic acids, orthoamidophenol nitro sult'onic acids, orthoamidophenol-chloro-sulfonic acids, orthoamidophenol disulfonic acids, or the likewith 1:5-amidonaphthol having the formula:

this process the goods are entered into boiling water and allowed to remain there until the water is cold. The goods thus assume a high degree of gloss and softness, and, according to the effect desired, the potting may be repeated several times.

In carrying out my process practicallyI can proceed as follows, the parts being by weight:

Nineteen parts of ortho-amidophenol-parasulfonic acid having the formula:

(W l I an excess of caustic-soda lye, care being taken that the mixture is always alkaline during the reaction. After being stirred for some time the excess of caustic-soda lye is neutralized by means of hydrochloric acid and the new dyestuff is precipitated by the addition of common salt, filtered off, and. dried.

The new coloring-matter thus obtained is in the shape of the sodium salt when dry and pulverized a brownish-black powder soluble in water and in alcohol to a reddish-violet solution and soluble in concentrated sulfuric acid of 66 Baum to a violet-red solution, a brownish-red precipitate being obtained therefrom by the addition of ice. It dyes wool from acid-baths brownish-violet shades. By subsequently treating the dyed fiber with chromium compounds reacting as oxidizing agents-such as chromates, bichromates, or the like-the shades are changed to black, distinguished for great fastness to the potting process. They'also resist milling and washing and possess a great fastness against the action of light.

Having now described my invention, what I claim is 1. The herein-described new azo dyestuifs derived from ortho-amidophenol derivatives havingthe above-given form ula and l :5-amidonaphthol which, when in a dry state, are brownish-black powders soluble in water with from a reddish-violet to bluish-violet color and dyeing Wool from acid-baths from violet tained therefrom by addition of ice; dyeing Wool from acid-baths brownish-violet shades which are changed to black by a subsequent treatment with chromium compounds reactv ing as oxidizing agents, substantially as described. v

In testimony whereof I have signed my name in the presence of two subscribing witnesses.

MYRTIL KAI-IN. Witnesses:

OTTo K6NIG, J. A. RITTERSHAUS. 

